


an unexpected agreement

by raspberryfrog



Category: Haikyuu!!
Genre: Alpha Ushijima Wakatoshi, Alpha/Beta/Omega Dynamics, Dom/sub Undertones, M/M, Omega Shirabu Kenjirou, Plot What Plot/Porn Without Plot, no beta we die like men, or like maybe overtones
Language: English
Status: Completed
Published: 2020-08-24
Updated: 2020-08-24
Packaged: 2021-03-06 15:28:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,388
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26091163
Author URL: https://archiveofourown.org/users/raspberryfrog/pseuds/raspberryfrog
Summary: Ushijima kneels next to the bed, and Shirabu is suddenly hit with his scent. He's familiar with it — earthy tones, summer thunderstorms and pine — but he’s never been around an alpha during his heat. It's aggressive, dominant, commanding. It sets every nerve in his body on fire, urging him to submit. Almost automatically, he turns his head to expose his neck, whining softly. He’s never wanted anything as badly as he wants Ushijima in this moment.
Relationships: Shirabu Kenjirou/Ushijima Wakatoshi
Comments: 19
Kudos: 164





	an unexpected agreement

**Author's Note:**

> i'm fully aware that shirabu isn't super popular (v valid, considering that he's a little shit) but i love him and also shirabu/ushijima has been in my head for like a week n i just had to write something ,, , anyway this is mostly self-satisfactory !

Shirabu slumps onto the bench in the locker room, his head in his hands. The rest of the team already went ahead to dinner, but he'd stayed behind, needing a moment to catch his breath. He's hot and cold at the same time, achy, and _tired_. He'd like to lie down and sleep for a few years. No doubt, his heat is fast approaching. 

Really, it's inopportune timing — of course, heats are never convenient, but for it to hit in the middle of a training camp is just plain bad luck. He briefly considers going down to the nurse before practice tomorrow to ask for temporary suppressants, but even with those, he'd still be drained. Washijo might bench him anyway, just because of his personal vendetta against omegas (Shirabu thinks it's because he hates being one). He discards the idea and resigns himself to calling in sick. 

The locker room door creaks open and he automatically turns to start shoving things into his duffel bag. He doesn't need anyone sticking their nose in his business at this exact moment. Ushijima appears from behind the lockers, bag slung over his shoulder.

Before Shirabu can say anything, he asks "Shirabu, can I speak with you?" 

“Huh? Sure, what’s up?” Shirabu runs through the events of the day in his head, wondering when he fucked up. 

“Is your heat about to start?” Shirabu isn't sure what he’d been expecting, but it sure as hell wasn’t that. He opens his mouth, then lets it snap closed again. 

“I — I’m not sure. It shouldn’t be until next week, but I’ve been having pre-heat symptoms,” he admits, feeling himself flush a little. It's not as though his omega status is a secret, but discussing it so frankly (with Ushijima, much less) is uncomfortable. “Why do you ask?”

“I can smell it.” Ushijima is always blunt, but _this_ , this is new. Shirabu’s face is burning. “If you can’t practice, it’ll set the entire team back.” God damn, Shirabu _knows_ that. It's not like he chose this for himself. He clenches his fists, but before he can respond, Ushijima hits him with yet another 80 mile-per-hour curveball. “If you need a heat partner, let me know.” He says it like he's offering to share his textbook or his lunch. If Shirabu wasn't so shocked, he would have laughed. 

“I, uh — yeah, I’ll think about it.” Seemingly satisfied, Ushijima nods and takes his leave. 

Shirabu thinks about it while he finishes packing up. Of course, having a heat partner would be nice. Not only would he be way less miserable, but he’d actually be able to practice with everyone else. But even so, Ushijima? It's not like he hasn’t thought about it before — Ushijima pinning him to the bed, broad shoulders looming overhead, dark green eyes clouded with lust. It makes for a pretty picture. 

But physical attraction aside, he isn't exactly close with Ushijima. They work well together as teammates, but outside of practice, they're acquaintances at best. He can only imagine it being awkward as hell. Sighing to himself, he tries to push it to the back of his head and heads to dinner. 

* * *

When Shirabu wakes up, the only light in the room is from his desk lamp. The clock in the corner shows 3:14 in blinking red numbers. He must have fallen asleep reading — his books are on the floor next to a tangle of sheets and blankets he’d kicked off in his sleep. 

He sits up and flinches at the unexpected trickle of slick between his legs. He stands to pick up his books, still thinking about Ushijima. He feels a little needy, but he knows it's nothing compared to what's coming. The slick means he probably only has another hour or two before it hits hard. He wonders if it's too late — Ushijima is probably asleep, anyway. 

Once he finishes remaking his bed, he turns off the light, grabs his phone, and wiggles back under the covers. He stares at Ushijima’s name in his contacts, biting his lip. Before he can chicken out, he starts typing out a message. 

> **To: Ushijima Wakatoshi**
> 
> _Were you serious about being my heat partner?_

No, that's stupid, Ushijima is always serious. He deletes the sentence. 

> **To: Ushijima Wakatoshi**
> 
> _So, you know how you offered to be my heat partner?_

Also stupid. He deletes that, too. He tries again, and again. And again. He's pretty sure his heat is getting to him. Finally, he settles on something simple and sends it before he can second guess himself. He curls into his blankets and tries not to think about it. 

* * *

Somehow, he must’ve fallen asleep, because he's woken by his phone buzzing. Immediately he knows his heat has hit (like a two-hundred ton freight train). He takes a shaky breath and fumbles for his phone. 

> **Me (3:37 AM)**
> 
> _Are you awake?_
> 
> **Ushijima Wakatoshi (6:34 AM)**
> 
> _I am now._
> 
> **Me (6:35 AM)**
> 
> _Can I take you up on that offer?_
> 
> _My heat just started_
> 
> _I don’t want to miss the rest of the training camp_
> 
> **Ushijima Wakatoshi (6:37 AM)**
> 
> _Sure. Should I come over now?_
> 
> **Me (6:37 AM)**
> 
> _Yes please_

With that, Shirabu sets his phone aside and sits up. Watery morning sunlight illuminates the room, casting long shadows. He can barely think. He stumbles to the door and unlocks it so that he won't have to collect himself when Ushijima arrives. Now, with his heat in full swing, the thought of Ushijima makes his legs tremble. Of course, he’s always admired Ushijima, lusted after him, even, but this is a different feeling. Something more primal, creeping underneath his skin and gathering in his belly. 

He falls back into bed face first, whimpering as his dick, already painfully hard, is pressed between his stomach and the mattress. Almost without thinking, he grinds down, rutting against the covers. The rational side of his brain screams at him to stop, because the last thing he needs is for Ushijima to walk in on him humping his bed like a fucking dog. Pathetic. 

It turns out not to be an issue (thankfully, because in the heat-induced haze, there's no way he's stopping), because it's not long before he comes in his shorts, panting. Rolling onto his back, he resists the urge to shove his fingers inside of himself, to do _something_ to assuage the aching emptiness. He clings to the thought that Ushijima is on the way, that he can provide more relief than his own fingers ever would. 

It feels like an eternity before he hears a knock at the door. He bites back a whimper, managing a quiet “come in.” Ushijima steps in and pauses to take in the scent of the room, eyelashes fluttering slightly. Decisively, he closes the door behind him, slips off his shoes, and covers the distance to Shirabu in a few long strides. 

He kneels next to the bed, and Shirabu is suddenly hit with Ushijima’s scent. He's familiar with it — earthy tones, summer thunderstorms and pine — but he’s never been around an alpha during his heat. It's aggressive, dominant, commanding. It sets every nerve in his body on fire, urging him to submit. Almost automatically, he turns his head to expose his neck, whining softly. He’s never wanted anything as badly as he wants Ushijima in this moment. 

Ushijima makes a soft noise of approval deep in his chest. Not for the first time, Shirabu finds himself thankful that Ushijima is such an unequivocally physical being. He holds his breath as Ushijima reaches up to run his fingers up Shirabu’s neck, pausing just under his jaw at his scent glands. He shudders as Ushijima rubs at them experimentally. 

Ushijima pulls away momentarily, sitting back on his heels. “You’re sure about this?” Someone else might’ve mistaken it for hesitation, but Shirabu knows Ushijima, and he knows he's just asking for confirmation; giving him a last chance to back out. 

Shirabu nods quickly, struggling to prop himself up on his elbows. “Yes, I’m sure.” He almost cringes at how fragile his voice sounds in comparison to Ushijima’s. 

Ushijima nods and rises, sliding his hands under Shirabu’s thighs to lift them. Shirabu falls back in surprise as Ushijima settles between his legs, trembling at the sudden closeness. If he was in his right mind, he would be blushing furiously. As it is, he can feel himself flush. 

Ushijima leans forward and nuzzles into the side of Shirabu’s neck, breathing him in. This close, Ushijima’s scent is overwhelming. Shirabu relaxes involuntarily, legs dropping open, eyelids heavy. He's warm and the bed is soft and Ushijima’s weight on top of him is oddly comforting. As Ushijima begins to lick at his scent glands, Shirabu surprises himself with a quiet purr. Clearly pleased, Ushijima gives an answering noise somewhere between a croon and a growl and his ministrations intensify, sucking harder to coax out more of Shirabu’s scent. When his teeth graze Shirabu’s neck, Shirabu shudders and clutches at the sheets to ground himself. Ushijima doesn't stop with the scenting until Shirabu is a trembling puddle on the bed, hyper-aware of the slick pooling in his underwear. 

Ushijima sits back, towering over him, and slides his hands under the hem of Shirabu’s shirt. He pushes it up, leaving Shirabu feeling strangely exposed, even though Ushijima has seen him without a shirt before (and many times, at that). He wants to cover himself, but something in the way Ushijima's eyes glint stops him. His pale chest is flushed to match his face, nipples pink. Decisively, Ushijima lifts his shirt the rest of the way off and tosses it to the floor. 

Quickly, his hands are back at Shirabu’s hips, sliding his shorts off and tossing them aside as well. Shirabu presses his legs together as a sudden surge of embarrassment rushes through him. He can feel slick dripping down to pool on the bedsheets, and he whines softly. Patiently, Ushijima slips his hands in between Shirabu’s thighs and pulls them apart. 

Shirabu can't help but cover his face as he trembles under the weight of Ushijima’s gaze, breath coming fast and shallow. Noting his discomfort, Ushijima leans forward to nose at his scent glands again and slowly coaxes his hands back down.

“Relax.” Shirabu can feel Ushijima’s chest vibrate as he speaks, his voice huskier than normal. Shirabu forces himself to breathe, to settle into the alpha’s scent. He trusts Ushijima to take care of him. Ushijima grunts in approval as Shirabu’s body softens against his. 

He pulls away, and almost before Shibaru knows what's happening, Ushijima is pushing his knees up to his chest. He feels Ushijima’s breath ghost across his bare thigh, and then he's lapping up the slick that has trickled down his inner thigh. 

“Ah, Ushijima-san, you—” he cuts himself off with a yelp as Ushijima sinks his teeth into the sensitive skin with a soft growl. Somehow, he knows what Ushijima wants. “S-sorry, a-alpha,” he stutters over the words, and Ushijima resumes his licking, slowly following the line of his thigh towards his ass. Shirabu shudders and tries again. “Alpha, you— you d-don’t have to—” he gasps as Ushijima’s tongue finds the tight ring of muscle. 

“I know. You taste good.” Shirabu flushes again. How Ushijima can say things like that without even batting an eye is beyond him. The thought is driven from his head as Ushijima licks over the hole again, warm and wet. Shirabu squirms as the alpha's tongue moves against his skin, but makes no movement to push inside. It's teasing, unintentionally cruel, and a sudden rush of desperation floods through Shirabu. 

“Alpha, p-please, inside…” Ushijima pulls away and Shirabu keens desperately at the loss of contact. He thinks he sees he corner of Ushijima’s mouth quirk up, but it's gone as soon as he blinks. Ushijima slips off his own shirt, tossing it to the side before he leans forward again, eyes dark and intense. Shirabu burns under his gaze but he can't look away, reveling in the flex of Ushijima's biceps and the broad solidness of his chest. 

Shirabu whimpers as Ushijima slowly presses a finger inside. He feels himself soften, his body opening to Ushijima like it's what he was born for. Ushijima takes his time exploring, prodding around inside Shirabu curiously. He grazes over Shirabu’s prostate and his cock twitches against his stomach. Ushijima pressed harder, experimentally, and Shirabu’s hips jump as he clenches down on his finger. He can't help the noise that escapes him, something pitiful and open-mouthed. It spurs Ushijima to press another finger inside, slowly settling into a rhythm as he stretches Shirabu open.

Shirabu falls apart under him, legs trembling, sweat beading on his chest. By the time Ushijima adds a third finger, he's leaking precum and panting softly along with each thrust. The movement of Ushijima’s fingers makes a lewd squelching noise — Shirabu might’ve been embarrassed if he were able to care. A few well-placed strokes send him over the edge, and he bears down around Ushijima’s fingers as he spills onto his stomach, trembling and trying not to make too much noise. Ushijima lets him ride his orgasm out, gaze unwavering, before he pulls out. He leans over to snag Shirabu’s discarded shirt and carefully wipes him clean. 

Once he's satisfied, he tosses the shirt to the side again and leans back. Shirabu whines at the loss of contact, but the sound dies in his throat as Ushijima steps off the bed and sheds his sweatpants. His cock bobs between his legs, just as large as the rest of him. Shirabu wants to taste it, to feel the weight of it against his tongue, bury his nose in the coarse hair at the base as he swallows around it. 

Ushijima steps forward, pausing at the edge of the bed expectantly. Understanding instinctively, Shirabu scrambles to present himself, pushing himself up on shaky legs, ass in the air, face buried in his pillow. He feels the mattress dip as Ushijima settles behind him. With one hand, he holds Shirabu’s hips steady, while he uses the other to guide his cock to Shirabu’s hole. He presses forward, and Shirabu gasps at the sudden burning, stinging stretch as Ushijima's cock drives into him. Tears begin to swell in his eyes, and as Ushijima continues to press in, Shirabu feels like he might split in half. Even so, it fulfills some carnal urge that he’s never been able to sate. He sighs, content, and lets himself go limp, held in place only by Ushijima’s firm grip. 

It seems like forever before Ushijima bottoms out, hips pressed gently against Shirabu’s ass. His breathing is labored, and he pauses to let Shirabu adjust. Shirabu has never felt this full — his own fingers could never compare — but nevertheless, after a few moments, it isn't enough. He needs Ushijima to move, to knot him, to claim him. He whines, wiggling in Ushijima’s grasp. Ushijima grunts in surprise but starts to move in slow, shallow thrusts. Shirabu can feel that he's holding himself back (uncharacteristic of him, Shirabu thinks). It still isn't enough. 

“More, alpha, p-please.” Ushijima’s grip tightens, drawing a whine from Shirabu, but he maintains his rhythm. He leans forward, pressing his chest to the plane of Shirabu’s back. His breath is warm, ghosting across Shirabu’s cheek.

“Are you sure? I won’t hold back.” 

His voice sends a shiver down Shirabu’s spine. “Yes, please.” He’s never been so sure about something. 

Ushijima snaps his hips forward, setting an unforgiving pace and pounding Shirabu into the mattress. Shifting his position, he leverages his weight to drive himself deeper, fucking into Shirabu like a toy. Each thrust forces a wordless sound from Shirabu’s lips as he surrenders himself to this new, animalistic side of Ushijima. Tears begin to slip down his cheeks, but he's content to let Ushijima do as he pleases.

Ushijima presses his nose into the side of Shirabu’s neck, licking and sucking at the skin there. Shirabu tips his head to the side in an effort to give him better access, and Ushijima growls, pleased, before biting down. Not hard enough to break skin, but hard enough to make Shirabu clench down on his cock. He feels slick drip down the inside of his thigh and whimpers softly. 

Pulling away a little, Ushijima hooks one arm around his hips and, with the other, reaches up to run his thumb across Shirabu’s lower lip. He shifts, slowly pressing two fingers into Shirabu’s mouth. Shirabu sucks on them greedily, content to be filled by his alpha. He ignores the trickle of drool running down his chin. When he curls his tongue around the digits, Ushijima groans and all but shoves them down his throat. Shirabu gags but makes no move to pull off, pliant in his grasp. He feels Ushijima’s knot beginning to swell, not yet large enough to hinder his movements. 

Ushijima withdraws his fingers, smearing spit across Shirabu’s cheek as he grips his chin, forcing him to turn his head. Before he knows what's happening, Ushijima’s mouth is pressed against his in a claiming, open-mouthed kiss, swallowing Shirabu’s moans. Ushijima licks into his mouth like he owns it, like he belongs as deep inside Shirabu as possible, in every way. His hand finds Shirabu’s hair and yanks, pulling his head back further for better access. 

When Shirabu sucks his alpha’s tongue further into his mouth, Ushijima’s hips stutter in their rhythm for the first time. With a growl, Ushijima breaks away and shoves Shirabu into the bed, thrusts growing erratic and sloppy, face pressed into the crook of Shirabu’s neck, knot catching on the rim of Shirabu’s hole with each thrust. Shirabu’s cock is trapped between his body and the sheets, and the sudden friction after being neglected for so long sends him quickly towards his climax. He _needs_ Ushijima to knot him, to stuff him full. 

“Alpha, p-please, knot me—” Shirabu is cut off as Ushijima comes, driving his cock as deep as he can, knot pressed against Shirabu’s prostate. He rides out his orgasm panting, moving as much as his knot will allow. Shirabu sobs as the pressure drives him over the edge, spilling over the sheets and clenching down around Ushijima’s knot. He can feel Ushijima’s cock pulse inside of him, and dully, he can feel himself being filled with cum. 

Sighing, Ushijima settles onto his side, pulling Shirabu close to his chest as they wait for his knot to go down. Shirabu lets himself relax into Ushijima’s warmth, feeling boneless. He runs a hand over his stomach curiously — he's pretty sure it's more swollen than usual. Pleased, he presses back further against Ushijima, relaxing in the afterglow. He feels safe, and warm, and happy. Again, he surprises himself with a purr. It's embarrassing, at first, but Ushijima's grip on him tightens ever so slightly, and he softens in his grasp. 

Eventually, Ushijima’s cock softens enough to slip out (an unpleasant sensation), followed by a trickle of cum (an even more unpleasant sensation). Ushijima pushes himself up and heads to the bathroom. Shirabu hears the sound of running water, and then he returns, carrying a damp washcloth. Wordlessly, he wipes Shirabu down with slow, careful movements. Shirabu watches him in nervous silence. After he's finished, he tosses the washcloth in with the rest of Shirabu's dirty laundry and starts pulling on his own clothes. 

When he realizes Shirabu isn't moving, he frowns. "You should get dressed. You need food." 

"Oh— oh, okay," Shirabu scrambles up, stumbling on unexpectedly weak legs, to grab some clean clothes. As he pulls a shirt over his head, he sneaks a glance at Ushijima, who is slipping on his shoes. "Ushijima-san?" Ushijima turns to look at him, but doesn't say anything. 

"Would you mind doing this again?" He blushes at the implication, while Ushijima's expression remains unreadable. "Just, you know, my heat comes in waves, so probably again tonight, I'll need—" he breaks off, too embarrassed to continue. 

Understanding, Ushijima nods. "As long as it doesn't get in the way of training." Shirabu nods quickly and Ushijima leads the way out of the room, headed to the dining hall. Shirabu follows close behind, desperately hoping their teammates won't pick up on anything.

**Author's Note:**

> thank you for reading :)) v much appreciated !!!


End file.
